GB2046794A - Silver and gold/silver alloy plating bath and method - Google Patents
Silver and gold/silver alloy plating bath and method Download PDFInfo
- Publication number
- GB2046794A GB2046794A GB8010924A GB8010924A GB2046794A GB 2046794 A GB2046794 A GB 2046794A GB 8010924 A GB8010924 A GB 8010924A GB 8010924 A GB8010924 A GB 8010924A GB 2046794 A GB2046794 A GB 2046794A
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- United Kingdom
- Prior art keywords
- bath
- silver
- aqueous bath
- aqueous
- potassium
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- 239000004332 silver Substances 0.000 title claims abstract description 23
- 229910052709 silver Inorganic materials 0.000 title claims abstract description 22
- 229910001316 Ag alloy Inorganic materials 0.000 title claims abstract description 13
- 238000000034 method Methods 0.000 title claims description 9
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 title description 7
- 239000010931 gold Substances 0.000 title description 7
- 238000007747 plating Methods 0.000 title description 5
- 229910001020 Au alloy Inorganic materials 0.000 title description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical group [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims abstract description 22
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000004327 boric acid Substances 0.000 claims abstract description 14
- 150000008044 alkali metal hydroxides Chemical class 0.000 claims abstract description 8
- 238000005282 brightening Methods 0.000 claims abstract description 8
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 8
- 239000000758 substrate Substances 0.000 claims abstract description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical group [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 33
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 239000002184 metal Substances 0.000 claims description 16
- 238000005275 alloying Methods 0.000 claims description 11
- 150000003839 salts Chemical class 0.000 claims description 11
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 8
- 229910017052 cobalt Inorganic materials 0.000 claims description 8
- 239000010941 cobalt Substances 0.000 claims description 8
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 8
- KZNICNPSHKQLFF-UHFFFAOYSA-N succinimide Chemical compound O=C1CCC(=O)N1 KZNICNPSHKQLFF-UHFFFAOYSA-N 0.000 claims description 8
- 239000003792 electrolyte Substances 0.000 claims description 6
- 238000009713 electroplating Methods 0.000 claims description 6
- HKSGQTYSSZOJOA-UHFFFAOYSA-N potassium argentocyanide Chemical compound [K+].[Ag+].N#[C-].N#[C-] HKSGQTYSSZOJOA-UHFFFAOYSA-N 0.000 claims description 6
- 229920002873 Polyethylenimine Polymers 0.000 claims description 5
- XTFKWYDMKGAZKK-UHFFFAOYSA-N potassium;gold(1+);dicyanide Chemical compound [K+].[Au+].N#[C-].N#[C-] XTFKWYDMKGAZKK-UHFFFAOYSA-N 0.000 claims description 5
- 229940100890 silver compound Drugs 0.000 claims description 5
- 150000003379 silver compounds Chemical class 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 claims description 4
- 239000000908 ammonium hydroxide Substances 0.000 claims description 4
- 229910052759 nickel Inorganic materials 0.000 claims description 4
- WQMVVOKCUPKPKL-UHFFFAOYSA-L potassium;silver;5-oxo-3,4-dihydropyrrol-2-olate Chemical compound [K+].[Ag+].[O-]C1=NC(=O)CC1.[O-]C1=NC(=O)CC1 WQMVVOKCUPKPKL-UHFFFAOYSA-L 0.000 claims description 4
- 229960002317 succinimide Drugs 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052785 arsenic Inorganic materials 0.000 claims description 3
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 230000008021 deposition Effects 0.000 claims description 3
- 229910052738 indium Inorganic materials 0.000 claims description 3
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 2
- 235000019253 formic acid Nutrition 0.000 claims description 2
- 229910052783 alkali metal Inorganic materials 0.000 claims 2
- -1 alkali metal gold cyanide Chemical class 0.000 claims 2
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Substances OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 claims 2
- 150000002940 palladium Chemical class 0.000 claims 2
- BJEPYKJPYRNKOW-REOHCLBHSA-N (S)-malic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O BJEPYKJPYRNKOW-REOHCLBHSA-N 0.000 claims 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 claims 1
- PXRKCOCTEMYUEG-UHFFFAOYSA-N 5-aminoisoindole-1,3-dione Chemical compound NC1=CC=C2C(=O)NC(=O)C2=C1 PXRKCOCTEMYUEG-UHFFFAOYSA-N 0.000 claims 1
- UEZVMMHDMIWARA-UHFFFAOYSA-N Metaphosphoric acid Chemical compound OP(=O)=O UEZVMMHDMIWARA-UHFFFAOYSA-N 0.000 claims 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims 1
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical compound OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 claims 1
- BJEPYKJPYRNKOW-UHFFFAOYSA-N alpha-hydroxysuccinic acid Natural products OC(=O)C(O)CC(O)=O BJEPYKJPYRNKOW-UHFFFAOYSA-N 0.000 claims 1
- 230000002708 enhancing effect Effects 0.000 claims 1
- 239000001630 malic acid Substances 0.000 claims 1
- 235000011090 malic acid Nutrition 0.000 claims 1
- 230000000087 stabilizing effect Effects 0.000 claims 1
- 238000004070 electrodeposition Methods 0.000 abstract description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 abstract description 2
- 230000000694 effects Effects 0.000 abstract description 2
- 150000002825 nitriles Chemical class 0.000 abstract description 2
- 230000006641 stabilisation Effects 0.000 abstract 2
- 238000011105 stabilization Methods 0.000 abstract 2
- 150000002466 imines Chemical class 0.000 abstract 1
- 229910052737 gold Inorganic materials 0.000 description 5
- 239000001508 potassium citrate Substances 0.000 description 4
- 229960002635 potassium citrate Drugs 0.000 description 4
- QEEAPRPFLLJWCF-UHFFFAOYSA-K potassium citrate (anhydrous) Chemical compound [K+].[K+].[K+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O QEEAPRPFLLJWCF-UHFFFAOYSA-K 0.000 description 4
- 235000011082 potassium citrates Nutrition 0.000 description 4
- 239000002253 acid Substances 0.000 description 3
- LGRDAQPMSDIUQJ-UHFFFAOYSA-N tripotassium;cobalt(3+);hexacyanide Chemical compound [K+].[K+].[K+].[Co+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] LGRDAQPMSDIUQJ-UHFFFAOYSA-N 0.000 description 3
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 239000002659 electrodeposit Substances 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 239000003353 gold alloy Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 2
- RXWQRLQUJZRVHB-UHFFFAOYSA-M silver;5-oxo-3,4-dihydropyrrol-2-olate Chemical compound [Ag+].[O-]C1=NC(=O)CC1 RXWQRLQUJZRVHB-UHFFFAOYSA-M 0.000 description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M sodium hydroxide Inorganic materials [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 2
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- RGHNJXZEOKUKBD-KLVWXMOXSA-N L-gluconic acid Chemical compound OC[C@H](O)[C@H](O)[C@@H](O)[C@H](O)C(O)=O RGHNJXZEOKUKBD-KLVWXMOXSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- ZPWVASYFFYYZEW-UHFFFAOYSA-L dipotassium hydrogen phosphate Chemical compound [K+].[K+].OP([O-])([O-])=O ZPWVASYFFYYZEW-UHFFFAOYSA-L 0.000 description 1
- 229910000396 dipotassium phosphate Inorganic materials 0.000 description 1
- 235000019797 dipotassium phosphate Nutrition 0.000 description 1
- 229960001484 edetic acid Drugs 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 239000002001 electrolyte material Substances 0.000 description 1
- 150000004674 formic acids Chemical class 0.000 description 1
- XGCKLPDYTQRDTR-UHFFFAOYSA-H indium(iii) sulfate Chemical compound [In+3].[In+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O XGCKLPDYTQRDTR-UHFFFAOYSA-H 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical class [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- IIQJBVZYLIIMND-UHFFFAOYSA-J potassium;antimony(3+);2,3-dihydroxybutanedioate Chemical compound [K+].[Sb+3].[O-]C(=O)C(O)C(O)C([O-])=O.[O-]C(=O)C(O)C(O)C([O-])=O IIQJBVZYLIIMND-UHFFFAOYSA-J 0.000 description 1
- CVHZOJJKTDOEJC-UHFFFAOYSA-N saccharin Chemical compound C1=CC=C2C(=O)NS(=O)(=O)C2=C1 CVHZOJJKTDOEJC-UHFFFAOYSA-N 0.000 description 1
- 229940081974 saccharin Drugs 0.000 description 1
- 235000019204 saccharin Nutrition 0.000 description 1
- 239000000901 saccharin and its Na,K and Ca salt Substances 0.000 description 1
- WYCFMBAHFPUBDS-UHFFFAOYSA-L silver sulfite Chemical compound [Ag+].[Ag+].[O-]S([O-])=O WYCFMBAHFPUBDS-UHFFFAOYSA-L 0.000 description 1
- GGCZERPQGJTIQP-UHFFFAOYSA-N sodium;9,10-dioxoanthracene-2-sulfonic acid Chemical compound [Na+].C1=CC=C2C(=O)C3=CC(S(=O)(=O)O)=CC=C3C(=O)C2=C1 GGCZERPQGJTIQP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/46—Electroplating: Baths therefor from solutions of silver
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/56—Electroplating: Baths therefor from solutions of alloys
- C25D3/64—Electroplating: Baths therefor from solutions of alloys containing more than 50% by weight of silver
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating And Plating Baths Therefor (AREA)
Abstract
Stabilization of an aqueous alkaline bath for electrode-position of silver or suitable silver alloys on a substrate, said bath essentially lacking in free cyanides and containing an imine brightening agent, said stabilization being achieved upon addition of boric acid and an ammonium or alkali metal hydroxide to effect a pH range of 8.0 to about 9.5; and the corresponding bath.
Description
SPECIFICATION
Silver and gold/silver alloy plating bath and method
The present invention relates to a method for improving the pH stability and brightening effect of an aqueous bath containing little or no free cyanide to be used for electrolytic deposition of silver or silver alloys; and the corresponding bath comprising an imine-type brightening agent, a soluble silver salt, 0-5% by weight of a soluble alloying metal salt, boric acid, and an ammonium or alkali metal hydroxide to adjust to a pH range of 8.0 to about 9.5.
The utilization of boric acid as a component in aqueous baths for the electrodeposition of various metals including silver and silver alloys, is generally known, Typical acid-type baths can be found, for example, in U.S. Patents 3,833,488, and 2,967,135.
The use of aqueous baths for electrodeposition which have a basic pH, that is, a pH greater than 7.0, however, are a more recent development. Attention is called, for example, to U.S.
Patent 3,864,222 which utilizes polyetheleneimines in gold and gold alloy baths to aid in maintaining the brightness of the metal deposit, and to permit extension of the pH range into the alkaline range. Unfortunately, however, the clear advantages of using imine-type brighteners in non-acid electrolytic baths, particularly in baths containing little or no free cyanide, must be presently balanced against serious attendant difficulties in controlling the pH of such baths.
Uncontrolled variations in pH often result in a dull, non-uniform electrodeposit plus rapid deterioration of the bath during use.
It is an object of the present invention to arrive at a method for minimizing pH shift during electrodeposition while still enjoying the advantages of an aqueous alkaline bath having low or no concentration of free cyanides.
It is a further object of the present invention to obtain a stable alkaline aqueous bath for electrodeposition of silver or silver alloys.
It has now been found that basic aqueous silver or silver alloy electroplating baths containing little or no free cyanide and comprising
(a) a soluble silver compound;
(b) 0 to about 5% by weight of a soluble salt of an alloying metal;
(c) an electrical conductivity-enhancing electrolyte; and
(d) an effective amount of an imine-type brightening agent can be effectively stabilized by adding thereto about .5-10% by weight of boric acid at at least one of an alkali metal hydroxide or ammonium hydroxide in an amount required to adjust the pH of the aqueous bath within the range of 8.0 to about 9.5, as desired.
For purposes of the present invention a suitable soluble silver compound for use in the bath can include almost any soluble silver compound such as, for example potassium silver cyanide, potassium silver succinimide, or a silver sulfite.
Where a silver alloy is to be electrodeposited, it is also found convenient to utilize up to 5% by weight, (inclusive of 0-5%) and preferably about .05 to about 20 grams of soluble salt of an alloying metal per liter of solution. For such purpose, the alloying metal can preferably, but not exclusively, include one or more of cobalt, nickel, copper, arsenic, indium, palladium, or other metals in addition to silver, depending upon the use intended for the resulting plated product.
Suitable electrical conductivity-enhancing electrolyte materials can be of the conventional type and include, for instance, salts of phosphoric, phosphonic, phosphenic, citric, malic, formic acids as well as optional additives, such as polyaminoacetic acids, organic phophinic acids, phosphoric acids or carboxymethylated derivatives of organic-phosphoric acids. Such electrolyte or electrolytes are conveniently present in the bath in amounts from about 20 to about 100 grams per liter of solution although not limited to such a range.
For purposes of the present invention, imine-type brightening agents are inclusive of cyclic or linear forms such as succinimide, or saccharin as well as a polyethyleneimine; an active amount for such purposes can usefully vary from about .1 %-3% by weight of solution. One or more of such agents can be utilized as desired.
The amount of boric acid for purposes of the present invention can usefully vary from about .5-10% by weight and is preferably used in the amount of about .5-5% by weight.
In addition to the above, the aqueous bath of the present invention can further contain chelating compounds such as cobalt or nickel sulfates or chelates of the base metals with nitrilotriacetic acid or ethylenediaminetetracetic acid and the like.
The pH of the bath is then adjusted within the range of 8.0 to about 9.5, as desired, and preferably to about 9.0 by the addition of an ammonium hydroxide or an alkali hydroxide such as sodium or potassium hydroxide.
Normally, electroplating by means of the present invention requires introduction of boric acid into the bath already containing the silver and/or alloying metal salts, adjustment of the pH of the bath from 8.0 to about 9.5 with an alkali metal hydroxide and the electroplating step effected onto a surface or metal substrate at a current density conveniently varying from about 1/2 to about 1 Q0 amperes per square foot at a temperature range from about 20"C to about 70"C, and preferably at about 60"C-70"C.
The aqueous baths so prepared may be used for the deposition of pure silver and/or silver alloys for jewelry and watch cases as well as for optical and industrial purposes and will provide excellent electrodeposit of a uniform deposit layer of silver and/or silver alloy by minimizing variations in bath pH during plating.
This invention will be better understood by reference to the examples which follow, although these examples are set forth merely to illustrate the practices of this invention and not intended in any way to limit the scope thereof.
EXAMPLE 1
An aqueous bath was formed which included the following:
Silver as potassium silver succinimide 24 g/I Potassium citrate 50 g/l
Succinimide 25 g/l
The pH of this bath was then adjusted to 9.0 with potassium hydroxide and the bath was electrolyzed at 5 amperes per square foot at room temperature, using insoluble anodes. The silver was replenished during electrolysis by addition of the silver succinimide complex. The pH of this bath fell from 9.0 to 7.5 after being electrolyzed for 2 ampere hours.
EXAMPLE 2
An aqueous bath was prepared which included the following:
Silver as potassium silver succinimide 24 g/l
Succinimide 25 g/l
Boric acid 30 g/l
The pH of this bath was adjusted to 9.0 with potassium hydroxide and the bath was electrolyzed at 5 amperes per square foot at room temperature, using insoluble anodes. The silver was replenished by addition of the silver succinimide complex. The pH of this bath remained constant at 9.0 after being electrolyzed for 6 ampere hours.
EXAMPLE 3
An aqueous bath was prepared which included the following:
Silver as the potassium silver cyanide 3 g/l
Gold as the potassium gold cyanide 1 2.3 g/l
Cobalt as the potassium cobalti cyanide 0.8 g/l
Polyethyleneimine 10 mg/l
Potassium citrate 30 g/l
The pH of this bath was adjusted to 9.0 with potassium hydroxide and the bath was electrolyzed at 5 amperes per square foot at room temperature. The pH of the bath increased from 9.0 to 10.4 in 12 ampere minutes.
EXAMPLE 4
A bath was prepared as in Example 3 except that potassium citrate was replaced with 30 g/l of boric acid. The pH of the bath was adjusted with potassium hydroxide to a pH of 9.0. The bath was then electrolyzed at 5 amperes per square foot at room temperature. The pH of the bath remained constant at 9.0 during 360 ampere minutes.
EXAMPLE 5
A bath was prepared which included the following:
Silver as potassium silver cyanide 2 g/l
Gold as potassium gold cyanide 8 g/l
Antimony as potassium antimony tartrate 1.5 g/l
Indium as indium sulphate 3.3 g/l
Nitrilo-triacetic acid 20 g/l
Potassium monohydrogen phosphate 25 g/l
Gluconic acid 50 mls/l The pH of this bath was adjusted with potassium hydroxide to 8.5. After electrolyzing this bath using insoluble anodes, the Ph increased from 8.5 to 10.2 in 12 ampere minutes.
EXAMPLE 6
Using the same formulation as in Example 5 with the addition of 30 g/l of boric acid neutralized with potassium hydroxide to pH 8.5, the bath was electrolyzed using insoluble anodes to deposit silver/gold alloys for 6 ampere hours with only a slight change in pH from 8.5 to 8.8.
EXAMPLE 7
A bath was prepared which included the following:
Silver as potassium silver cyanide 3 g/l
Gold as potassium gold cyanide 12.3 g/l
Cobalt as the potassium cobalti cyanide 0.8 g/l
Potassium citrate 25 g/l
Polyethyleneimine 10 mg/l
The pH of this bath was adjusted to 9.0 with potassium hydroxide. After 1 5 ampere minutes of plating, the pH of this bath rose from 9.0 to 10.3.
EXAMPLE 8
Using the same formulation as in Example 7 and adding 25 g/l of boric acid neutralized with potassium hydroxide to pH 9.0, the bath was electrolyzed using insoluble anodes. The pH of the bath was maintained at 9.0 after 2 ampere hours of plating.
EXAMPLE 9
A bath containing the following components was prepared:
Silver as potassium silver cyanide 3 g/l
Gold as potassium gold cyanide 12.3 g/l
Cobalt as potassium cobalti cyanide 0.8 g/l
Polyethyleneimine 10 mg/l
Boric acid 30 g/l
The pH was adjusted to 9.0 with potassium hydroxide and the bath was electrolyzed at 5 amperes per square foot at room temperature. There was no change in pH, after 6 ampere hours.
As will be obvious to one skilled in the art many alterations, modifications and variations can be made in the practices of this invention without departing from the spirit and scope thereof as set forth in the claims which follow.
Claims (14)
1. A stable, substantially free cyanide-free aqueous bath for electrolytic deposition of silver or a silver alloy onto a metal substrate which bath comprises
(a) a soluble silver compound;
(b) 0 to 5% by weight of a soluble salt of an alloying metal;
(c) an electrical conductivity-enhancing electrolyte;
(d) an effective amount of an imine-type brightening agent;
(e) 0.5-5% by weight of boric acid; and
(f) at least one member alkali metal hydroxide or ammonium hydroxide in an amount required
to adjust the pH of the aqueous bath to from 8.0 to 9.5.
2. An aqueous bath as claimed in Claim 1 which contains no alloying metal salt.
3. An aqueous bath as claimed in Claim 1 which contains a soluble cobalt, nickel, copper, arsenic, inidium or palladium salt as an alloying metal salt.
4. An aqueous bath as claimed in Claim 1, in which component (b) is an alkali metal gold cyanide.
5. An aqueous bath as claimed in Claim 4 which contains from 0.05 to 20 grams per liter of potassium gold cyanide; and 0.05 to 20 grams per liter of boric acid.
6. An aqueous bath as claimed in any preceding Claim wherein said alkali metal hydroxide is potassium hydroxide.
7. An aqueous bath as claimed in any preceding Claim wherein the pH is about 9.0.
8. An aqueous bath as claimed in any preceding Claim wherein the silver is present as potassium silver cyanide or potassium silver succinimide.
9. An aqueous bath as claimed in any preceding Claim wherein the brightening agent is a polyethyleneimine or succinimide.
10. An aqueous bath as claimed in any preceding Claim wherein said electrical conductivity enhancing electrolyte is at least one salt of phosphoric, phosphonic, phosphenic, citric, malic, or formic acid.
11. An aqueous bath as claimed in any preceding Claim which additionally contains a cobalt or nickel chealating compound.
1 2. An aqueous bath as claimed in Claim 1 and substantially as hereinbefore described with reference to any of Examples 2, 4, 6, 8 or 9.
1 3. A method for stabilizing a basic aqueous silver or silver alloy electroplating bath containing little or no free cyanide and
(a) a soluble silver compound;
(b) from 0 to 5% by weight of a soluble salt of an alloying metal;
(c) an electrical conductivity-enhancing electrolyte; and
(d) an effective amount of an imine-type brightening agent; which comprises adding thereto from 0.5-5% by weight of boric acid and at least one of an alkali metal hydroxide or ammonium hydroxide in an amount required to adjust the pH of the aqueous bath to from 8.0 to 9.5.
14. A method as claimed in Claim 1 3 wherein the electroplating bath contains a soluble cobalt, nickel, copper, arsenic, indium, or palladium salt as an alloying metal.
1 5. A method as claimed in Claim 1 3 wherein the electroplating bath contains no alloying metal salt.
1 6. A method as claimed in Claim 1 3 wherein the bath contains an alkali metal gold cyanide.
1 7. A method as claimed in Claim 1 and substantially as hereinbefore described with reference to any of Examples 2, 4, 6, 8 or 9.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US2717779A | 1979-04-04 | 1979-04-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB2046794A true GB2046794A (en) | 1980-11-19 |
Family
ID=21836140
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8010924A Withdrawn GB2046794A (en) | 1979-04-04 | 1980-04-01 | Silver and gold/silver alloy plating bath and method |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS55134191A (en) |
| AR (1) | AR225759A1 (en) |
| AU (1) | AU5717880A (en) |
| BR (1) | BR8001854A (en) |
| DE (1) | DE3013191A1 (en) |
| DK (1) | DK146980A (en) |
| FR (1) | FR2453226A1 (en) |
| GB (1) | GB2046794A (en) |
| IT (1) | IT1127414B (en) |
| NL (1) | NL8001999A (en) |
| SE (1) | SE8002598L (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0239876A1 (en) * | 1986-03-20 | 1987-10-07 | DODUCO GMBH + Co Dr. Eugen DÀ¼rrwächter | Bath for electroplating silver-palladium alloys |
| EP1024211A2 (en) * | 1999-01-19 | 2000-08-02 | Shipley Company LLC | Silver alloy plating bath and a method of forming a silver alloy film by means of the same |
| US20130023166A1 (en) * | 2011-07-20 | 2013-01-24 | Tyco Electronics Corporation | Silver plated electrical contact |
| EP3023520A1 (en) * | 2014-11-21 | 2016-05-25 | Rohm and Haas Electronic Materials LLC | Environmentally friendly gold electroplating compositions and methods |
| US20230357945A1 (en) * | 2020-08-19 | 2023-11-09 | Eeja Ltd. | Cyanide-based silver alloy electroplating solution |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH051393A (en) * | 1990-07-19 | 1993-01-08 | Electroplating Eng Of Japan Co | Silver-copper alloy plating bath and silver-copper alloy brazing filler metal |
| ES2117995T3 (en) * | 1994-02-05 | 1998-09-01 | Heraeus Gmbh W C | BATH FOR GALVANIC DEPOSIT OF SILVER-TIN ALLOYS. |
| DE4406419C1 (en) * | 1994-02-28 | 1995-04-13 | Heraeus Gmbh W C | Bath for the electrodeposition of silver-gold alloys |
| JP4919430B2 (en) * | 1999-12-02 | 2012-04-18 | 株式会社日本キャリア工業 | Meat shredding equipment |
| CN102560571B (en) * | 2012-02-22 | 2015-08-05 | 江苏大学 | Non-cyanide silver coating stable electrical plating solution, preparation method and silver-plated method thereof |
| CN103741178B (en) * | 2014-01-20 | 2017-06-16 | 厦门大学 | A kind of solution and electro-plating method for the smooth fine and close Ag films of silicon face Direct Electroplating |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2410441C2 (en) * | 1974-03-01 | 1982-11-11 | Schering Ag, 1000 Berlin Und 4619 Bergkamen | Cyanide-free bath and process for the electrodeposition of silver |
| JPS52105540A (en) * | 1976-03-01 | 1977-09-05 | Tech Inc | Silver bath for lusterous plating of nonncyanide |
| US4088549A (en) * | 1976-04-13 | 1978-05-09 | Oxy Metal Industries Corporation | Bright low karat silver gold electroplating |
| US4121982A (en) * | 1978-02-03 | 1978-10-24 | American Chemical & Refining Company Incorporated | Gold alloy plating bath and method |
-
1980
- 1980-03-27 BR BR8001854A patent/BR8001854A/en unknown
- 1980-04-01 GB GB8010924A patent/GB2046794A/en not_active Withdrawn
- 1980-04-01 AR AR280528A patent/AR225759A1/en active
- 1980-04-02 JP JP4207680A patent/JPS55134191A/en active Pending
- 1980-04-02 FR FR8007437A patent/FR2453226A1/en not_active Withdrawn
- 1980-04-02 DK DK146980A patent/DK146980A/en not_active IP Right Cessation
- 1980-04-02 IT IT48317/80A patent/IT1127414B/en active
- 1980-04-03 NL NL8001999A patent/NL8001999A/en not_active Application Discontinuation
- 1980-04-03 SE SE8002598A patent/SE8002598L/en not_active Application Discontinuation
- 1980-04-03 DE DE19803013191 patent/DE3013191A1/en not_active Withdrawn
- 1980-04-03 AU AU57178/80A patent/AU5717880A/en not_active Abandoned
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0239876A1 (en) * | 1986-03-20 | 1987-10-07 | DODUCO GMBH + Co Dr. Eugen DÀ¼rrwächter | Bath for electroplating silver-palladium alloys |
| EP1024211A2 (en) * | 1999-01-19 | 2000-08-02 | Shipley Company LLC | Silver alloy plating bath and a method of forming a silver alloy film by means of the same |
| EP1024211A3 (en) * | 1999-01-19 | 2003-03-05 | Shipley Company LLC | Silver alloy plating bath and a method of forming a silver alloy film by means of the same |
| US20130023166A1 (en) * | 2011-07-20 | 2013-01-24 | Tyco Electronics Corporation | Silver plated electrical contact |
| EP3023520A1 (en) * | 2014-11-21 | 2016-05-25 | Rohm and Haas Electronic Materials LLC | Environmentally friendly gold electroplating compositions and methods |
| US20230357945A1 (en) * | 2020-08-19 | 2023-11-09 | Eeja Ltd. | Cyanide-based silver alloy electroplating solution |
Also Published As
| Publication number | Publication date |
|---|---|
| IT1127414B (en) | 1986-05-21 |
| SE8002598L (en) | 1980-10-05 |
| DK146980A (en) | 1980-10-05 |
| AU5717880A (en) | 1980-10-09 |
| JPS55134191A (en) | 1980-10-18 |
| NL8001999A (en) | 1980-10-07 |
| BR8001854A (en) | 1980-11-18 |
| IT8048317A0 (en) | 1980-04-02 |
| FR2453226A1 (en) | 1980-10-31 |
| AR225759A1 (en) | 1982-04-30 |
| DE3013191A1 (en) | 1980-10-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |